personaly i've always liked sealed boxes for the tight, and solid bass. to me it just sounds more natural, its not like it cant hit that low rumble down in the 30hz range it just doesnt exagerate it. At least thats how i always felt about ported or vented boxes.
so i'd like to see some other views, its not an argument just personal preference.

for the last four or five years i've had 2 dual voice coil 12 inch Comp-VR's in the back with 800watts @ 2ohm feeding them in there own seperate sealed boxes.

What it comes down to really is that given the small space available inside a car, it's often impossible to vent a decent high-excursion woofer, both in terms of available volume, and in terms of physically fitting the vent into a smallish box.

Also, with cabin gain, sealed boxes match up better with this natural boost.

Tight / solid bass IMO comes simply from the correct design of box, and implementation of crossover and integration, rather than box sealed vs vented per se.

i think it depends on orientation of the box....i think sealed boxes sound best the farther away they are from you, crushing lows.

i always use vented boxes though, for me its easier to tune and tailor the taste to a customers liking. Alot of people dont listen to the kind of music that has alot of sub bass, and prefer strong midbass, starting in the upper bass region, just coming out of the sub bass region.....sub and port face are really important here.

you can tune a ported box to one octave above a sub bass frequency, and it will still play the low notes(just not as strong)....and not unload like most people think...depends on actual box volume.

i usually stay away from making bandpass boxes for customers because in the wrong hands they are sub killers.

Mainly because i feel that a large woofer (15") in a sealed box x over`ed low (50-60hz) and in combination with dedicated midbass drivers (8") gives less mechanical noise from the vehicle and doesent give the subbox away as rear mounted.

My former setup with dual ported 10`s didnt give me as much satisfaction as my current solution.

More rattles, less deep bass, and much easyer to locate as a rear mounted box, and didnt even sound snappier than my current sealed 15"

What bothers me the most is that 95% of people install their subs in the trunk, completely isolated from cabin, and then talk about SQ bass when ALL they can hear is muddy superposition of sound waves and a lot of interference.

In my understanding, the perfect bass should punch you directly into the chest and take your breath away but it MUST NOT make your seats vibrate or make wowowowow –standing-wave like sounds of retarded rap music.

I tried building both vented and sealed enclosures but I was not satisfied with sound because as soon as I turned off my speakers to listen to the bass alone - it was horrible sounding. I experimented a lot with moving my sub enclosure and figured out that one of the best places was between the front seats oriented directly at the windshield. It minimized the amount of seat vibrations and gave me clarity that I was looking for. Also, ALL of the external car noises were gone. However, even though the bass became a lot clearer, it was less punchy compared to subs in the trunk, so I had to quadruple the amplifier power to get the clean, chest-pounding reflection off of the windshield that I was looking for.

I ended up using single JL 10W6v2 sub powered by JBL bpx1100.1 in 1.25 ft^3 sealed enclosure.